Top 9 Interesting Facts About Planet Mars

#4. We need to breathe oxygen

Earth’s atmosphere is about 78 percent nitrogen and 21 percent oxygen, with trace amounts of water vapor, carbon dioxide and other gases. By comparison, Mars’ atmosphere is 95 percent carbon dioxide. “We need to breathe oxygen,” said planetary scientist Pascal Lee, who’s based at NASA’s Ames Research Center. There’s no free oxygen in the Martian atmosphere.